JERUSALEM — They have been labeled “Hardakim,” a derogatory term that combines Haredim, the name commonly used in Israel to denote ultraorthodox Jews, with the Hebrew words for insects and germs.

As the Israeli government presses ahead with plans to enlist young Haredi men and phase out their wholesale exemption from the country’s mandatory military service, hard-line elements in the ultraorthodox community are fighting back by ostracizing the few thousand community members already in the armed forces.

Crude, comics-style posters have appeared in recent weeks on billboards across ultraorthodox neighborhoods nationwide portraying those soldiers, who volunteered under programs meant to attract Haredim, as fat, bearded, gun-toting caricatures in uniform snatching terrified Haredi children off the streets.

The strictest Haredim, who insist on the right of all ultraorthodox men to engage in full-time Torah study and worry about exposure to a more secular life, denounce the soldiers as “traitors” and liken them to a pestilence.

Brig. Gen. Gadi Agmon, from the Israeli military’s human-resources branch, told a parliamentary committee in Jerusalem last week that the well-orchestrated campaign was no less vicious in style than that of Der Stürmer, the Nazi-era propaganda organ notorious for its anti-Semitic caricatures. The remark was widely reported in the secular news media and on Haredi websites.

Haredi soldiers have been orally abused, spit on and humiliated while walking through their neighborhoods. Some have been attacked with stones, or their car tires have been slashed. The children of others have been rejected by local educational institutions, and there are growing fears that enlisting could harm the marriage prospects of their siblings.

The integration of Haredim, or “those who fear God,” into the military — and providing them a path into the workforce — is viewed as essential by many Israelis, not only to uphold the principle of social equality but also to ensure the economic survival of the country. More than one-quarter of Jewish first-graders in Israeli schools belong to the fast-growing ultraorthodox minority.

In recent years, hundreds have served in Nahal Haredi, a combat battalion established in the late 1990s for ultraorthodox 18-year-olds. About 3,000 more have served in Shahar, an army program set up in late 2007 to train young married ultraorthodox men as technical staff members for the air force, navy, intelligence and other branches of the military.

To attract recruits, Shahar allows soldiers to go home every night during their two-year army stint and provides a government salary.

But with Parliament working on legislation that would eventually lead to the conscription of ultraorthodox men, and the subsequent backlash among the Haredim, things now appear to be moving in the opposite direction.

In past years, the ultraorthodox community was more tolerant toward members who chose military service; some rabbis even gave their quiet blessing to recruits who were deemed unsuitable for full-time Torah study. But Haredi attitudes have hardened in response to the broad public pressure and government efforts to work toward equal service for all, barring a small quota of Orthodox youths considered Torah prodigies.

In May, up to 30,000 Haredi men flooded the streets around the recruitment office in Jerusalem to protest conscription, exposing for the first time the depth of anger. The Haredi reaction already appears to have dampened volunteer enlistment.

Elchanan Fromer, 29, who is from a small ultraorthodox settlement in the West Bank and works as a coordinator for the Shahar program, said the year began well, with more than twice as many volunteers as in the first half of 2012. But he said in recent weeks he’s seen signs of a drop-off.

Fromer joined Shahar in 2010 and served for 18 months. But service has become harder for Haredi soldiers, he said, because of the inflamed passions and potential consequences for their families.

“Hundreds of soldiers are facing daily problems,” he said. “Personally, if I was supposed to enlist today, I wouldn’t do it.”

On billboards in the ultraorthodox Mea Shearim quarter of Jerusalem last week, black-and-white posters warned the public against the “licentious military” coming to tempt innocent Haredi youths into “the whorehouses of Nahal and Shahar.”

On central thoroughfares, the posters of children being snatched had mostly been ripped off the walls. But in the back alleys, where one hostile resident threw water from a balcony onto reporters, the posters remained untouched. Since most Haredim do not watch television, billboards and fliers are a traditional means of communication.

Pini Rozenberg, a spokesman for the Haredi community in Jerusalem, said the campaign was “an internal Haredi matter meant to explain to the Haredi youth why the army institutions are not, and will never be, legitimate.”

He added: “It is not personally directed against any particular soldier. It is purely educational.”

Rozenberg insisted rabbis who support the campaign behind the scenes oppose any form of violence.

But Haredi critics of the campaign point out that the rabbis, like most ultraorthodox Jews, have remained silent, allowing more extreme community members to set the tone.